TABLE OF CONTENTS In the last 20 years several new innovative methods of separation have been introduced and are being developed for resource recovery from mineral and metallurgical wastes. Many of these techniques, based on physico-chemical principles originated and were applied in other separation processes such as separation of organic molecules and biochemicals of importance in pharmaceutical industry. The introduction of new technologies is driven by two main considerations. First is the constant search for improving the process efficiency, to maximize the recovery and selectivity. Secondly, the recovery of resources from complex materials and from dilute effluents where the concentrations of the desired compounds is below the limit recoverable by conventional techniques requires development of new technology, which can lead to their recovery also resulting in a cleaner effluent discharged in the environment. Some of these innovative developments in resource recovery will be discussed in this Chapter.
Magnetic carriers are magnetic materials designed to bind selectively on a non-magnetic material to be able to separate using magnetic separation techniques (described in Chapter 2). By this approach, magnetic separation technology can be applied to the separation of materials that are otherwise non-magnetic. Magnetic carrier technology originated in 1940s, when magnetite was used to remove organic impurities from wastewater streams using electrostatic adsorption (Urbain and Steman, 1941). A generic term for this technology is magnetic support technology as it incorporates magnetic supports, which are materials, which have the property of selectively enhancing the magnetic properties of the target non-magnetic material that...
